KR20170083553A - A flue gas purification device - Google Patents

Abstract

The present invention relates to a flue gas purifying apparatus, and more particularly to a so-called wet flue gas purifying apparatus in which flue gas is treated with a liquid absorbent, that is, a liquid such as seawater.

Description

{FLUE GAS PURIFICATION DEVICE}

The present invention relates to a flue gas purifying device, in particular a so-called wet flue gas purifying device, wherein the flue gas is treated with an alkaline liquid, such as a liquid absorbent, i.

These wet flue gas purifiers should be distinguished from devices operating with slurries (such as limestone suspensions) as absorbents.

A purifying apparatus operating as a slurry is disclosed in WO96 / 00122. Flue gas flows through a perforated plate on which an absorbent limestone suspension fluidized bed is provided. A similar arrangement is disclosed in US 4,099,925.

A flue gas purifying device in which seawater is used as the absorption liquid is shown in EP 264 252 A1. The apparatus includes a scrubber tower (also referred to as an absorption tower) in which flue gas and seawater contact each other. The spent seawater is then collected by gravity into the sump-shaped area beneath the scrubber tower. According to EP2644252A1, a sump-shaped region can be a part of a flow-channel for seawater.

It is clear that the perfusion channel is not necessarily a part of the flue gas purifier integrated into the flue gas purifier, and as described below in connection with the prior art and the present invention, the area below the scrubber tower is considered part of the flue gas purifier do.

Equipment and processes using seawater have a number of advantages over apparatus and processes that operate as limestone suspensions as sorbents for sulfur oxides in flue gases, such as:

- Liquid absorbents, such as seawater, contain a very small amount of solids and therefore have a very low risk of occlusion.

- Seawater is inexpensive.

- It is very easy to condition the absorbent (Aufbereibung in German) using seawater.

- It is not necessary to dispose of sea water outside.

- After re-adjusting the pH value of the seawater, the seawater can be returned to the ocean.

 Nonetheless, there is a continuing need to improve purification apparatus and methods that use such seawater. One key point is to simplify the overall structure, especially the scrubber towers and the area of contact between the sorbent and the flue gas.

The present invention aims to improve the conventional purification apparatus and method using such seawater, and in particular to simplify the overall structure, in particular, to simplify the area of contact between the scrubber tower and the absorbent and the flue gas.

By the design of the flue gas purifying apparatus according to claim 1, which comprises the following arrangement, not only the advantages of a wet flue gas purifying apparatus using seawater as a liquid absorbent can be maintained, but also additional advantages can be achieved Proven.

A flow-through channel for the liquid sorbent extending in the horizontal direction,

- a flue gas distributor immersed in the liquid absorbent along the longitudinal extension of said perfusion channel,

The flue gas distributor comprising at least one flue gas inlet and a plurality of flue gas outlets,

A flue gas collector vertically spaced above the flue gas outlet of the flue gas distributor.

Additional advantages include:

A (padded) contact zone with which the sorbent liquid contacts the flue gas moves from the scrubber tower over the sump region to "within the sump region ". That is, the flue gas and seawater contact within at least one section of the perfusion channel, the function of transporting fresh seawater to the purifier and the function of the spent (spent) seawater in subsequent processing units and / Or back to the sea.

Pipes and pumps (and corresponding energy) for transporting fresh seawater to the contact area within the tower can be omitted. Fresh sorbents can flow self-sufficient (autarkic) towards the flue gas distributor along the perfusion channel and continue to flow through the distributor and / or around the distributor and continue in substantially one substantially common direction Lt; RTI ID = 0.0 > longitudinally < / RTI > In order to allow the absorbent to "self-flowing" in the channel, the bottom of the channel may be formed with a slight inclination in the horizontal direction.

The nozzles for dispensing fresh seawater into the contact zone of a corresponding scrubber tower with untreated flue gas may be omitted.

A contact zone is provided by a flue gas distributor that is functionally located (immersed) in the seawater stream.

(Seawater after contact with flue gas) that is significantly lower than the pH of fresh seawater (e.g., in the range of 7-8) (e.g., in the range of 3-4) (In the range of 7-8) of fresh seawater, i.e. the portion of the seawater stream not in contact with the flue gas from the seawater stream discharged from the distributor. As a result, the pH of this seawater mixture is increased again, post-processing to return the seawater to its original pH of the seawater or to bring it close to its original pH is easy and requires less configuration work. Since a scrubber tower with jet nozzles and a pump for providing seawater to these jet nozzles can be omitted and thus little energy is required for the seawater stream, It is possible to provide a larger amount of fresh seawater. The "excess" of these fresh seawater has the added benefit of significantly increasing the correlation between seawater and gas (S / G) and thus more effectively removing SO ₂ .

The device according to EP 2644252 A1 can be easily modified (reconstructed). The injection nozzles in the scrubber tower can be removed or maintained as additional means and / or auxiliary means for bringing the sorbent and flue gas into contact with each other. The injection nozzles can be used for secondary treatment of the pre-cleaned flue gas on the way from the gas distributor (contact zone) to the gas outlet via the gas-collector. The scrubber tower may be used as a flue gas collector and / or as a flue gas extractor.

Since the absorber liquid stream flowing along the channel is defined by itself as originating from the ocean, the flue gas distributor is an important component in achieving the best purification result.

The flue gas distributor is located in a lotic absorbent. In theory, the flue gas will be sufficient to to escape into the surrounding liquid by any of the outlet means from the dispenser, in this respect at first glance, the design of the dispenser but less important, to up to a cargo, particularly SO ₂ sulfuric acid in flue gas A wide contact area between the flue gas and the liquid is desirable for removal. This can be accomplished by converting the flue gas stream entering the distributor into individual small gas bubbles (splitting). In this respect, the flue gas capacity of industrial flue gas purifiers is, for example, from 1,000,000 to 3,000,000 m3 / hr and the required fluid absorbent is from 15,000 to 200,000 m3 / hr.

Accordingly, embodiments of flue gas distributors have one or more of the following features.

The flue gas distributor extends over a large area in the horizontal direction to allow the flue gas to flow into the fluid absorbent stream over a large surface area so that the flue gas and the sorbent can contact over a large area. In an apparatus having the above-described performance data, the size of the distributor (electric field / width / height) may be 2-30 m each.

The flue gas distributor is designed such that a liquid absorbent (seawater) can flow through the flue gas distributor in a direction substantially corresponding to the main flow direction of the liquid absorbent along the perfusion channel before and after the contact space. That is, the flue gas distributor is at least partially permeable to the liquid sorbent.

This "permeability" can be realized by forming an opening in the outer wall of the distributor, in particular in the sections adjoining each other, as well as in the section defining the upper end (in the vertical direction). In the case of a cubic splitter, these openings can be formed in all six wall sections (or five sections in the case of a bottomless distributor).

The cross-section (shape) of these openings can be any shape. For example, the cross-section of the openings may be rectangular, elliptical, circular. The quantity and size of the openings may vary depending on the volume of flue gas supplied into the distributor and the volume of flue gas exiting the distributor through these openings. In these industrial purifiers, openings with respective cross-sectional areas between 1 and 15 cm2 are considered effective in increasing the contact area between the flue gas and the absorbent. Sieve-like wall sections meet the same specifications.

The flue gas inlet (inlet) of the flue gas distributor is arranged such that the flue gas flows into the flue gas distributor in a substantially horizontal direction. This reduces the transport cost of the flue gas and allows the flue gas to be well dispersed within the distributor. The flue gas may be fed into the distributor via one, two or more inlet pipes. Based on the above capability data, the cross-section of this inlet duct may be about 5 x 10 m.

In order to evenly distribute the untreated flue gas into the distributor, it is advantageous to center the inlet of the inlet duct (with respect to the overall distributor design).

The wall of the flue gas distributor is inclined downward toward the outer rim of the flue gas distributor. This design allows the dispenser to be dome-shaped and allows a greater amount of gas to be trapped in the dome space before the flue gas is discharged into the liquid via the openings.

The total cross-sectional area of these openings as well as the quantity and size of the openings may vary depending on the wall section. If the distributor surfaces are downwardly and outwardly, the total cross-sectional area of the openings in the outer wall sections may be greater than the total cross-sectional area of the central section to allow a greater amount of flue gas to escape under the outer wall sections. That is, the total cross-sectional area of the openings in the wall per square meter increases as the distance from the center point of the distributor increases. Here, the center point represents a geometrical center.

These parameters (size, shape, quantity, cross-sectional area per area) are combined in various manners so that the performance of each of the purifier and the distributor can be maintained constantly and steadily. That is, these parameters can be adjusted so that the flue gas flows constantly and steadily into the liquid on each distributor surface.

In addition to the urgent situation, it is advantageous if the gas volume is unexpectedly large, so that the excess flue gas can escape to this floor by means of a distributor with no floor or channel bottom open.

To enable the liquid and the gas to make an even and even contact, other purification device embodiments are characterized by having guiding means within the distributor and / or along the distributor. As described above, the liquid flows in one main flow direction in the channel, i.e., in the longitudinal direction of the channel. So that the guiding means follow this longitudinal extension, i.e. the direction substantially parallel to the channel axis. The guide means may be a metal plate. The metal plates can be fixed to the distributor. The dispenser can be made of a liquid absorbent material such as metal, concrete, etc., and a material that can withstand flue gas.

Fresh seawater absorbs SO ₂ from the flue gas while the flue gas flows through the liquid in the channel, and the flue gas thus purified must then be collected. The purifier includes a flue gas collector spaced above the distributor for collecting the flue gas and directing it to a subsequent facility such as a mist eliminator, chimney or the like. The flue gas collector must project the distributor horizontally.

According to another embodiment, the horizontal extension of the flue gas collector overlaps the distributor at least at its downstream end. In this way, any residual flue gas (or other gas / air) in the seawater can rise and escape the seawater stream and be captured into the main flue gas stream.

The lower end of the flue gas collector may be disposed protruding into the channel surface or into the channel fluid in the channel.

In order to allow the liquid to flow substantially continuously and steadily in the channel, it is advantageous to additionally provide a weir-shaped body in the perfusion channel. By this dam, the flow cross-sectional area for the fluid absorbent can vary, and in particular, the dam can be adjusted (e.g., moved) relative to the cross-section of the perfusion channel.

A seawater mixture can aeration downstream of the distributor before the seawater mixture is discharged to the ocean. Again, this aeration step may be performed in the perfusion channel according to the contact step.

Other features of the invention may be derived from the dependent claims and the following detailed description and the drawings.

1 is a side view of a flue gas purifying apparatus.
2 is a top view of the flue gas distributor.

1 shows a flue gas purifying apparatus having the following features.

A liquid-phase absorbent, that is, a flow-through channel (10) for seawater, extends in the horizontal direction. The upstream and downstream of the perfusion channel are considered to be independent components, and the portion shown in Figure 1 is considered to be part of the flue gas purifier. Within the channel 10, the sea level is indicated by two parallel lines with triangles on top.

The metallic flue gas distributor 12 is placed (locked) in the seawater along the longitudinal extension L of the flow-through channel 10 with a width W (not shown) and a height H (bottom to liquid level) have.

The flue gas distributor 12 has two flue gas inlets 14 disposed on either side of the flue gas distributor 12. Only one flue gas inlet (flue gas inlet) 14 is visible in Fig.

The width (perpendicular to the length L in the horizontal direction) of the flue gas distributor 12 of length L is slightly smaller than the corresponding width W of the flow-through channel 10. [ On the other hand, the height h of the flue gas distributor 12 is about half the height H of the liquid (seawater) in the flow-through channel 10. The specific data of the distributor is L = 20m, width = 10m, h = 5m.

The flue gas distributor (12) further comprises a top plate (16) extending in the horizontal direction. In the top panel, four wall sections denoted by reference numerals 18, 20, 22 and 24 in Fig. 2 extend outwardly and downwardly.

Absorbent material passing through the flow-through channel 10 from left to right (as indicated by arrows A1, A2) may pass through the top plate 16 and the wall sections 18, 20, 22, 24. Gas and water permeate through the circular holes (openings) 26 of the distributor walls 16, 18, 20, 22, 24. The diameter of the circular holes is 3 cm. The quantity of openings 26 is calculated according to the incoming flue gas volume so that it enters the flue gas distributor 12 through the inlet 14 and exits the flue gas distributor 12 through the openings 26 .

As shown in FIG. 1, the flue gas distributor 12 is generally submerged in the absorbent liquid.

A flue gas collector 30 extends from the flue gas channel 10 and overlies the flue gas distributor 12 along the entire circumference of the flue gas distributor 12. The lower end 301 of the flue gas collector 30 protrudes into the liquid stream 11 to provide a gas seal.

The flue gas collector 30 overlaps the flue gas distributor 12 at the upstream end 12u and the downstream end 12d of the flue gas distributor 12 at its lower end and the flue gas distributor 12 at the downstream end 12d, Is considerably larger than the overlapping portion at the upstream end 12u.

This provides a channel section 11 downstream of the downstream end 12d of the flue gas distributor 12 which is covered by the flue gas collector 30 and which remains in the liquid stream All the air / gas is collected by the flue gas collector 30.

The optional configuration of the device is indicated by dotted line 40. That is, this option configuration allows the injection nozzle to inject additional seawater into the collector space by its spray nozzle. However, in most cases these additional nozzles may be omitted.

The purification process is as follows.

Fresh seawater is transported through the channel 10 to the channel section below the flue gas collector 30 (arrow 1).

Because the flue gas distributor 12 is bottomless, the space delimited by the top plate 16 and the walls 18, 20, 22, 24 is filled with seawater passing through the perfusion channel 10.

Untreated raw flue gas enters the flue gas distributor 12 via the inlet duct 14 and exits the flue gas distributor 12 through the openings 26 to the flue gas distributor 12 Before being flowed into the seawater absorbent on the outside, it is dispersed into the space delimited by the top plate 16 and the walls 18, 20, 22, 24.

The space in the distributor 12 and the area around the distributor 12 define the contact zone of the absorbent liquid (seawater) and the flue gas.

Thus, the flue gas further rises in the seawater before the treated (contacted) flue gas enters the collect chamber 30 and continues to be guided in the subsequent facility, such as a chimney.

It is clear from the description of the invention that only a portion of the seawater comes into contact with the flue gas. This allows the spent (consumed) seawater to come in contact with the fresh seawater immediately after the flue gas and fresh seawater contact, thereby allowing the seawater mixture to escape downstream from the distributor.

Figure 1 additionally shows a dike-shaped facility 50 disposed at the bottom 10b of the flow-through channel 10. The dam can be inflated such that the height in the vertical direction can be adjusted according to the desired seawater passing through the perfusion channel 10.

There may also be additional treatment steps downstream (not shown in FIG. 1), such as an aeration basin (as part of the perfusion channel or as an individual component) before the seawater is discharged to the ocean.

Fig. 2 further shows the guiding means 60. Fig. In which the guiding means are arranged below the distributor 12 (or in addition to it on the distributor 12) to support the flow direction of the seawater and extend in the flow direction of the absorption in the flow channel 10.

Claims (13)

A liquid-phase absorbent flow-through channel 10 extending in the horizontal direction,
A flue gas distributor (12) immersed in the liquid absorbent along the longitudinal extension (L) of the flow-through channel (10)
The flue gas distributor 12 has at least one flue gas inlet 14 and a plurality of flue gas outlets 26,
And a flue gas collector (30) vertically spaced above the flue gas outlet (26) of the flue gas distributor (12) and vertically spaced above the liquid absorbent in the flue gas channel Flue gas purifier. The method according to claim 1,
The flue gas distributor 12 is configured to allow the liquid sorbent to flow through the flue gas distributor 12 in a direction substantially corresponding to the main flow direction of the liquid sorbent along the flow- Wherein the flue gas purifying device is designed such that the flue gas purifying device is designed. The method according to claim 1,
Wherein the flue gas distributor (12) is permeable to the liquid sorbent. The method according to claim 1,
Characterized in that the flue gas inlet (14) of the flue gas distributor (12) is arranged such that flue gas is introduced into the flue gas distributor (12) in a substantially horizontal direction. The method according to claim 1,
Characterized in that the flue gas distributor (12) comprises walls which are inclined downwardly towards the outer rim of the flue gas distributor (12). The method according to claim 1,
Wherein the flue gas distributor (12) is a dome-like shape. 6. The method of claim 5,
Wherein the flue gas outlet (26) of the flue gas distributor (12) is designed with discrete openings. The method according to claim 1,
Characterized in that the total cross-sectional area per square meter of discrete openings (26) increases with increasing distance from the flue gas inlet (14). The method according to claim 1,
Characterized in that the flue gas collector (30) extends horizontally above the flue gas distributor (12). The method according to claim 1,
Characterized in that the flue gas collector (30) extends horizontally over and above the flue gas distributor (12). The method according to claim 1,
Characterized in that the flue gas collector (30) comprises guide means (60) extending in the longitudinal direction of the flow channel (10) and spaced from each other in a direction perpendicular to the longitudinal direction. The method according to claim 1,
Characterized in that the flue gas distributor (12) has its lower vertical end open. The method according to claim 1,
(50) in the flow-through channel (10) to reduce the flow cross-sectional area of the liquid absorbent flowing along the flow-through channel (10).

Images